Silent chain

Abstract

A rocker-joint silent chain in which the pin insertion holes for each link have rocker-joint connecting pin means extending therethrough. Each pin insertion hole has two opposed, spaced-apart surfaces each having the cross-section form of arcs of uniform radius. The centers of curvature of said two surfaces are offset from one another so that they define an arcuate, but noncircular, cavity which is effective to wedge said connecting pin in load-transmitting relationship to its associated link when the chain is driven.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A silent chain which comprises a plurality of link plates, each link plate having a plurality of teeth and being connected at its opposite ends to adjacent link plates by means of a pair of rocker-joint connecting pins, said link plate having a rocker-joint connecting pin insertion hole, a traction load-transmitting, side, inner surface of said rocker-joint connecting pin insertion hole being formed into a nonload-transmitting surface portion which does not contact the rocker-joint connecting pin and two load-transmitting concave surface portions which are located on opposite ends of said nonload-transmitting surface portion, are continuously connected thereto and extend away therefrom and are contacted and coupled with a rocker-joint connecting pin disposed in said insertion hole and contacting said concave surface portions, said load-transmitting concave surface portions consisting essentially of two, circular arc, concave surfaces which have different centers of curvature, said two, circular arc, concave surfaces facing each other so as to form a wedge-shape portion of said pin insertion hole. 
     
     
       2. A silent chain of the rocker-joint type, comprising an endless series of elongated links each having inverted teeth thereon, rocker-joint connecting structures connecting each link to the adjacent links at opposite longitudinal ends thereof, respectively, each of said rocker-joint connecting structures comprising a pin insertion hole having a rocker pin extending therethrough in the longitudinally inner section of said hole and a seat pin extending therethrough in the longitudinally outer section of said hole, the inner periphery of said hole having a closed, continuous, smoothly curved, concave surface free of convexities, said seat pin and said rocker pin having adjacent, transversely extending surfaces which rockably contact each other so that said seat pin can rock with respect to said rocker pin, said longitudinally outer section of said hole consisting of a concave, central, circumferential surface portion and two concave, end, circumferential surface portions which extend smoothly and continuously in opposite circumferential directions away from the opposite circumferential ends of said central surface portion, said concave end surface portions being disposed in opposed relation to each other and having the cross-sectional shape of circular arcs in which the centers of curvature of the respective circular arcs are offset from each other so that said end surface portions define therebetween a cavity which has a continuous smooth wall, is noncircular in cross-section and forms a wedge zone, said seat pin having a central, circumferential surface portion which is opposed to and is spaced inwardly from said concave, central, surface portion of said hole so as to be in nonload-transmitting relationship thereto, said seat pin having two convex, end, circumferential surface portions extending smoothly and continuously in opposite circumferential directions away from the opposite circumferential ends of said central surface portion, said convex end portions of said seat pin being disposed between, being opposed to and contacting said concave end surface portions of said hole, said convex end portions of said seat pin having the same size and shape as said concave end surface portions of said holes, respectively, so as to be complementary thereto whereby said seat pin can be wedged in said wedge zone with said convex end portions of said pin being in load-transmitting relationship to said concave end surface portions of said hole. 
     
     
       3. A silent chain comprising: a plurality of link plates, each link plate having a plurality of teeth and being connected at its opposite ends to adjacent link plates by a pair of rocker-joint connecting pins, said link plate having a rocker-joint connecting pin insertion hole;   said insertion hole defining a traction load-transmitting side inner surface having a central non-load-transmitting surface portion which does not contact the rocker-joint contacting pin and two load-transmitting concave surface portions which are located on opposite ends of said nonload-transmitting surface portion, said two load-transmitting concave surface portions being continuously connected to and extending away from opposite ends of said non-load transmitting surface portion, said two load-transmitting concave surface portions being contacted and coupled with a rocker-joint connecting pin disposed in said insertion hole;   said load-transmitting concave surface portions consisting essentially of first and second circular arc concave surfaces which are generated respectively about first and second radii which respectively have different first and second centers of curvature, said first and second circular arc concave surfaces facing each other so as to form a wedge-shaped portion of said pin insertion hole, and said first and second centers of curvature being spaced apart from one another generally toward the opposite concave surfaces so that said first and second radii intersect during generation of the respective first and second concave surfaces.   
     
     
       4. A silent chain according to claim 3, wherein said first and second radii are equal. 
     
     
       5. A silent chain according to claim 3, wherein said first and second radii are unequal.